Automatic weather alerts: what they are and how they work

Checking the forecast several times a day works. Until you stop doing it. The problem is usually not access to weather data. Today, there are many sources for checking temperature, rain, wind, or storms. The problem begins when you need to know whether a specific condition will occur in one or more fields and do not want to rely on remembering to check the forecast constantly. That is where an automatic weather alert comes in.

An alert is not a different forecast

An automatic alert does not need to create its own forecast. It can work with existing weather data and do something different with it: evaluate it against a rule. For example:

• Notify me if the temperature falls below 2 °C.
• Notify me if wind gusts exceed 45 km/h.
• Notify me if accumulated rainfall exceeds 20 mm.
• Notify me if the temperature rises above 36 °C.

The forecast provides the data. The rule determines which data deserves your attention.

The first step is defining a condition

In Vienor, alerts are configured for each field. Each rule has an event type, a threshold, and a time window. This turns something broad like “I want to keep an eye on the weather” into a specific condition. For example:

I want to know whether the temperature in this field could fall below 3 °C during the next 24 hours.

Once the rule is defined, you do not need to interpret it again every time the forecast changes. The system can do that automatically.

What happens after you create the rule

Vienor periodically retrieves the hourly weather forecast for the field. Currently, this process runs every 30 minutes. During each cycle, the system updates the data and evaluates the active rules again. In simplified terms, the process works like this:

1. Vienor retrieves the updated forecast for the field.
2. It reviews the hourly data within the configured window.
3. It compares those values with the active rules.
4. It detects whether any condition reaches or exceeds its corresponding threshold.
5. When appropriate, it generates an alert.
6. It sends a notification according to the user's preferences.

The user does not need to have the platform open while this process takes place.

What conditions can Vienor monitor?

The alert engine currently supports five main event types.

Frost

The rule is triggered when the forecast temperature is equal to or below the configured threshold.

Wind

Forecast wind gusts are monitored and compared with the limit defined by the user.

Rain

Vienor adds up the forecast precipitation within the time window and identifies the condition when the total reaches the threshold.

Heat

The rule looks for temperatures equal to or above the configured value.

Convective storms

CAPE is used as the main indicator of instability, with additional weather information providing context for the event. Each event follows different logic because weather variables are not all interpreted in the same way.

Rules work on each field

Location is one important difference between these rules and a general weather alert. Vienor does not require you to work only with the name of a city. The user can draw the field's geometry on the map. Rules are then associated with that field. This makes it possible to maintain different criteria for different locations. One field can have a frost rule with one threshold, while another uses a different configuration.

Why the system evaluates rules again every 30 minutes

A forecast does not remain static. As new data arrives and models are updated, forecast conditions can change. A storm can shift. The forecast low can rise or fall. Expected rainfall totals can change. That is why Vienor does not evaluate a rule once and then abandon it. The forecast is updated periodically and the conditions are analyzed again. Currently, the evaluation cycle runs every 30 minutes.

That does not mean receiving an alert every 30 minutes

Updating the forecast frequently and sending notifications frequently are two different things. If the same rule for the same field has already generated an alert recently, Vienor applies deduplication logic. For a three-hour window, it avoids creating another identical alert for that same condition. The goal is to keep monitoring the forecast without turning a persistent situation into a stream of repeated notifications.

How severity is determined

Not every condition that crosses a threshold has the same intensity. A temperature just below the configured limit is not the same deviation as one several degrees lower. The same applies to wind, rain, and heat. Vienor therefore classifies alerts into different severity levels:

• Low
• Medium
• High
• Critical

The level is calculated according to how far the forecast condition deviates from the defined threshold. Besides knowing that a rule was triggered, the user gets a reference for the magnitude of the detected event.

What the user receives

When an alert is generated, Vienor can notify the user by push notification and email. The message does not contain only the name of the event. It can also include relevant data about the detected condition. For example, a wind alert can include gust speed and direction. A rain alert can show the expected total and, when appropriate, precipitation probability. A frost alert can include temperature, humidity, and wind for context. The exact information depends on the event type.

Preferences matter too

Not every user needs to receive the same notifications. Vienor lets each user enable or disable push notifications and email, define a minimum severity, and select the types of alerts that interest them. This is especially important when several people belong to the same organization. Fields and rules belong to the organization, but each user can adjust how they want to receive information.

An alert still depends on a forecast

Automating monitoring does not eliminate weather uncertainty. Vienor evaluates forecasts. It does not know with certainty what will happen in the future, nor does it replace a weather station installed in the field. If the model changes, the forecast condition can change too. Automation solves a different problem: constantly checking the forecast for a particular condition.

How far ahead the system looks

The alert engine currently works with hourly forecasts extending up to 72 hours ahead. This sets the maximum horizon for active alerts. It does not mean that every event will appear three days in advance. A condition may emerge in the forecast much closer to the event. The lead time depends on the forecast and the time window configured for the rule.

From checking data to monitoring rules

This is the central idea behind an automatic alert. It is not about having another place to check the weather. It is about telling the system which conditions you want it to look for on your behalf. The forecast remains available. But you no longer need to review it manually every time to find out whether a temperature, rainfall total, or wind speed that requires your attention has appeared.

Configure your own alerts in Vienor

Vienor lets you create field-specific weather rules for frost, wind, rain, heat, and convective storms. The system updates the forecast and evaluates the conditions again automatically every 30 minutes. If a rule is met, it can notify you by push notification or email according to your preferences.

Try Vienor free for 30 days, with no credit card required.